Products > Test Equipment
Review and tear-down of UNI-T UT612 LCR meter
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Wytnucls:
The Applent AT825 is more expensive, doesn't power-up or charge from a USB 5V connection and lacks the all important 100kHz test frequency. Not a good trade-off in my book.
Of course, if measuring low value resistors is most of what you do, then a proper 4W system is better. Even then, as I have shown, errors are within 30mOhms on the UT612, which has a best resolution of 1mOhm on the 20 Ohm range.
Shielding is useful for measuring resistor values over 10M with long test leads, but not much else. The UT612 comes with shielded tweezers anyway.
The LCD screen is not an issue really, but if your meter was faulty then I understand your frustrations. I couldn't find your past eBay transaction where you presumably listed the problems with your meter though.
MarkPalmer:
Take a look at the tables in the back of the Uni-T’s manual.  You will see that just like Agilent’s 100 kHz handheld LCR model it doesn’t have much to offer as far as ranges go at its 100 kHz test frequency, and even what it does offer is at a high percentage of error at 100 kHz.  The Applent AT's include a regular AC charger.  I don't consider a USB charger to be any sort of standard necessity with any test equipment myself or any form of a disadvantage without USB charging. As Applent manufactures a lot of sophisticated battery testing instruments, I imagine they felt it to be safest to not feature USB charging.

-Mark-
HiTech:

--- Quote from: Wytnucls on September 16, 2014, 04:47:13 pm ---The Applent AT825 is more expensive, doesn't power-up or charge from a USB 5V connection and lacks the all important 100kHz test frequency. Not a good trade-off in my book.
Of course, if measuring low value resistors is most of what you do, then a proper 4W system is better. Even then, as I have shown, errors are within 30mOhms on the UT612, which has a best resolution of 1mOhm on the 20 Ohm range.
Shielding is useful for measuring resistor values over 10M with long test leads, but not much else. The UT612 comes with shielded tweezers anyway.
The LCD screen is not an issue really, but if your meter was faulty then I understand your frustrations. I couldn't find your past eBay transaction where you presumably listed the problems with your meter though.

--- End quote ---
1.  In all practicality, how often does any hobbyist (or even the professional tech for that matter) need to test capacitance at 100KHz? Perhaps some esoteric switching power supply caps? 10KHz is plenty for the most part IMHO and I will quickly trade that seldom needed feature for the bright, color TFT display of the Applent - and a touch display at that!

2.  For my needs, 4-wire ohms measurement is better accomplished and trusted using my older Fluke 8085A or my Datron any day, before that from a Uni-T product. I didn't but the UT-612 to measure low value resistance.

3.  As for the laggy response of the meter, it's my overall "perception" of it compared to others I've tried. It seems to require more "communications" or measurement time before displaying the results.

4.  You have to admit it's peculiar and noteworthy about the viewing angle issue of the LCD display that seems to plague all production units of the UT612. Gosh, even the LCD display of cheapo $3 DMM that Harbor Freight Tools often gives away for free has good contrast at most any angle. So after some use, yes, the UT612's goofy display became an annoyance to me. I don't want to spend time positioning a meter to effectively view it.... especially when all the other test equipment on my bench needn't that silly bit of attention! Appears to me Uni-T decided to gamble and compromise rather than reject the whole lot of LCD displays. Given that, makes me wonder where/how else they may have compromised on that model?

5.  As for eBay, the meter isn't truly faulty. I simply don't like it's overall response and the bogus 4-wire clips that are sold under the premise as being Kelvin.
Wytnucls:
Not quite.
The inductance measurement has an extra range at 100KHz (20uH), with a resolution of 0.001uH and the same accuracy of 1%+5.
The capacitance measurement range goes down to 200pF for both frequencies with an accuracy of 2%+5.
But it is not only a matter of low ranges, some components have to be tested at 100KHz to properly compare readings to datasheet specs.
That is why high-end LCR meters have a wide range of test frequencies. Some small thin film caps call for a test frequency of 1MHz.

As for the USB connection, it might not bother you to carry an extra wall wart, but it is hard to deny the inconvenience. The safety issue is probably worse for your AC wall charger.

Wytnucls:
AFAIK, the UT612 was never advertised as being equipped with a Kelvin connection. The tweezers provided are shielded though and so are the UNI-T clips sold on the internet. Some unscrupulous sellers advertised them as Kelvin, but if you know your meter, it is easy to tell that it has no 4 wire connections: The middle jacks are clearly marked 'GUARD'.

The peculiar LCD screen has been discussed at length. The CEM LCR meter screen is just the same. I really don't think it matters that much, but I understand that some people may be unhappy with it.

I see that some UT612 are available for 120$ or less on eBay now, with free shipping:
http://www.ebay.com/itm/UNI-T-UT612-Multi-purpose-LCR-Meter-Inductance-Capacitance-L-C-R-DCR-Q-D-ESR-/221392747637?pt=LH_DefaultDomain_0&hash=item338c093c75

And yours of course, with the Kelvin clips  ;) :
http://www.ebay.com/itm/Uni-T-UT612-digital-LCR-meter-/171457846139?pt=LH_DefaultDomain_0&hash=item27ebaf1b7b 
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